Table 2.

Results from different studies on the effect of Na gene (% live weight) on different strains at different ages and temperatures on body weight, dressing yield, feather weight, breast, and abdominal fat percentages.

Age	Genotype	Temperature Ranges (°C)	Gene Effect 1 on Parameters (% Live Weight)					References
			Body Weight	Dressing Yield	Feather	Breast	Abdominal Fat
16 wk	Nana vs. nana	23–27 °C	+9.29%		−18.47%	+6.85%	−49.50%	[70] *
16 wk	NaNa vs. nana	23–27 °C	+6.82%		−43.18%	+9.54%	+59.60%	[70] *
49 d	Nana vs. nana	24–32 °C	+2.4%		−19.0%	+6.4%		[59] *
49 d	NaNa vs. nana	24–32 °C	+0.3%		−38.9%	+6.4%		[59] *
42 d	Nana vs. nana	19–26 °C	+0.5%		−10.2%		+16.7%	[71] *
42 d	Nana vs. nana	28–37 °C	+0.16%		−26.45%		−28.62%	[71] *
8 wk	Nana vs. nana	summer-autumn Max. 40–42 °C		−0.95%			=	[67] **
10 wk	Nana vs. nana	summer-autumn Max. 40–42 °C		+0.19%			+18.6%	[67] **
12 wk	Nana vs. nana	summer-autumn Max. 40–42 °C		+0.28%			+6.55%	[67] **
6 wk	Nana vs. nana	28.7–32.5 °C	+3.04%	+1.05%		+8.09%	+0.10%	[68] *
43 d	NaNa/Nana vs. nana	12–30 °C	+0.22%	+5.6%	−25.47%	+0.5%	−6.28%	[61] *
43 d	NaNa/Nana vs. nana	32–45 °C	+8.0%	+4.37%	−34.16%	+3.1%	−20.37%	[61] *
20 wk	Nana vs. nana	26.9 °C	+5.72%	+5.48%	+5.56%			[62] **
20 wk	NaNa vs. nana	26.9 °C	+3.83%	+6.96%	+7.74%			[62] **

¹ Gene effect of naked neck genotypes = $\frac{\left(\mathrm{N}\mathrm{a}\mathrm{n}\mathrm{a} \mathrm{o}\mathrm{r} \mathrm{N}\mathrm{a}\mathrm{N}\mathrm{a}\right)-\left(\mathrm{n}\mathrm{a}\mathrm{n}\mathrm{a}\right)}{\mathrm{n}\mathrm{a}\mathrm{n}\mathrm{a}}\times 100$; * Trial in experimental conditions; ** Trial in commercial conditions.